ii. What mass in grams of sodium trioxocarbonate (IV) is needed to prepare 250 cm³ of 0.2 moldm³ solution?…

Question

ii. What mass in grams of sodium trioxocarbonate (IV) is needed to prepare 250 cm³ of 0.2 moldm³ solution? [Na = 23, O=16, C=12]

ScanSolve AI Tutor · Accepted Answer

here are the solutions to the chemistry questions:

4. (a) i. What is a buffer solution?
A buffer solution is a solution that resists significant changes in pH when small amounts of an acid or a base are added. It typically consists of a weak acid and its conjugate base, or a weak base and its conjugate acid.

4. (a) ii. Give two uses of buffer solution.

Maintaining the pH of blood and other biological fluids.
Controlling the pH in industrial processes, such as fermentation and dyeing.

4. (b) i. Name the process used in the production of ammonia.

Haber process

4. (b) ii. Give two physical properties of nitrogen.

It is a colorless gas.
It is an odorless gas.

4. (b) iii. List the two allotropes of carbon.

Diamond
Graphite

4. (b) iv. Mention the structure of each allotrope in (b)iii.

Diamond: Each carbon atom is covalently bonded to four other carbon atoms in a tetrahedral arrangement, forming a giant covalent network structure.
Graphite: Each carbon atom is covalently bonded to three other carbon atoms in a trigonal planar arrangement, forming hexagonal layers. These layers are held together by weak intermolecular forces.

4. (b) v. Give one use of charcoal.

Used as a fuel.

4. (c) i. Give the general molecular formula for:
I. Alkenes: $\boxed{\text{C}_n\text{H}_{2n}}$
II. Alkynes: $\boxed{\text{C}_n\text{H}_{2n-2}}$

4. (c) ii. Write out the possible structural isomers of $\text{C}_4\text{H}_{10}$ .
I. $\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3$
II. $\text{CH}_3\text{CH}(\text{CH}_3)\text{CH}_3$

4. (c) iii. Give the IUPAC names of the isomers in (c)ii.
I. $\boxed{\text{Butane}}$
II. $\boxed{\text{2-Methylpropane}}$

4. (c) iv. Calculate the molecular formula of a compound with the following composition by mass; 60% carbon, 13.3% hydrogen and 20.7% oxygen with a molar mass of 60.
Note: The given percentages (60% C, 13.3% H, 20.7% O) sum to 94%. For the problem to be consistent with a molar mass of 60 g/mol, we assume the oxygen percentage is $100\% - 60\% - 13.3\% = 26.7\%$ .

Determine the mass of each element in 100 g of the compound.
Mass of C = 60 g
Mass of H = 13.3 g
Mass of O = 26.7 g (assumed)
Convert the mass of each element to moles.
$\text{Moles of C} = \frac{60 \text{ g}}{12 \text{ g/mol}} = 5 \text{ mol}$ $\text{Moles of H} = \frac{13.3 \text{ g}}{1 \text{ g/mol}} = 13.3 \text{ mol}$ $\text{Moles of O} = \frac{26.7 \text{ g}}{16 \text{ g/mol}} \approx 1.66875 \text{ mol}$
Determine the simplest whole-number mole ratio by dividing by the smallest number of moles.
The smallest number of moles is 1.66875 (for Oxygen).
$\text{Ratio C} = \frac{5}{1.66875} \approx 2.996 \approx 3$ $\text{Ratio H} = \frac{13.3}{1.66875} \approx 7.97 \approx 8$ $\text{Ratio O} = \frac{1.66875}{1.66875} = 1$
The empirical formula is $\text{C}_3\text{H}_8\text{O}$ .
Calculate the empirical formula mass.
$\text{Empirical formula mass} = (3 \times 12) + (8 \times 1) + (1 \times 16) = 36 + 8 + 16 = 60 \text{ g/mol}$
Determine the molecular formula.
The given molar mass is 60 g/mol. Since the empirical formula mass (60 g/mol) is equal to the molar mass (60 g/mol), the molecular formula is the same as the empirical formula.
The molecular formula is $\boxed{\text{C}_3\text{H}_8\text{O}}$ .

Ii. What mass in grams of sodium trioxocarbonate (IV) is needed to prepare 250 cm³ of 0.2 moldm³ solution? [Na = 23, O=16, C=12]

Step-by-step solution

Determine the mass of each element in 100 g of the compound.

Convert the mass of each element to moles.

Determine the simplest whole-number mole ratio by dividing by the smallest number of moles.

Calculate the empirical formula mass.

Determine the molecular formula.

Still stuck on this one?

More Chemistry Questions